1. Field of the Invention
The invention relates to crosslinkable substances based on organosilicon compounds and comprising encapsulated biocides, to processes for the preparation thereof and to the use thereof.
2. Background Art
Single-component sealants which are storable with the exclusion of water and which vulcanize on exposure to water at ambient temperature to give elastomers are well known. These products are used in large amounts, for example in the construction industry. Growth of organisms such as fungi and algae readily occur on the surface of the sealants, in particular in surroundings of high atmospheric humidity, for example in bathrooms or kitchens, but also, for example, in tropical regions. In order to prevent this growth, fungicides or biocides are added to the sealants.
However, the use of many biocides in pure form is problematic since interactions with other ingredients may occur, for example with amine adhesion promoters, and may result in discolorations, vulcanization problems and reduced effectiveness, e.g. reduced fungicidal effectiveness.
The biocides must be able to diffuse to the surface in order to be able to act in that vicinity. This diffusion is thus associated with fairly rapid leaching of the active substance and accordingly a fairly rapid loss of biocidal effectiveness. If an attempt is made to counteract this by a high concentration of the free active substance, this generally results in ecological problems and also in increased product cost.
Furthermore, some biocides can only be used with UV stabilizers. A mixture of free active substance and UV stabilizer in the composition does not, however, effectively prevent the decomposition of the active substance by UV light during storage.